undefined reference to `Config::SingleLinkedList::staticMetaObject' and `vtable for Config::SingleLinkedList'

[Limer]

class ConfigBase : public QWidget, it has slots and signals, so Q_OBJECT is set in the code.

Now, class SingleLinkedList : public ConfigBase , it also has its own slots and signals, so Q_OBJECT is also set in the code. But i come across one problem.

error: undefined reference to `Config::SingleLinkedList::staticMetaObject'

error: undefined reference to `vtable for Config::SingleLinkedList'

collect2.exe:-1: error: error: ld returned 1 exit status

I googled many, but no use.

If you want all the project(it is a little project, but is not convenient to public), leave your email !

[SGaist]

Hi,

Did you add/remove the Q_OBJECT macro at some point ? If so you should re-run qmake or do a full rebuild.

[Limer]

@SGaist

I tried, no use.

[aha_1980]

@Limer said in undefined reference to `Config::SingleLinkedList::staticMetaObject' and `vtable for Config::SingleLinkedList':

class ConfigBase : public QWidget, it has slots and signals, so Q_OBJECT is set in the code.

Hello, is your class defined in a header or in a cpp file?

If it's in a header file, try deleting the whole build folder (make sure there are no Makefiles left, neither in the source nor in the build folder).

If the definition is in a cpp file, then you will have to include the generated .moc file your own by apppending something like #include "singlelinkedlist.moc" at the end of your cpp file.

[Limer]

@aha_1980

In a heaer file. I tried, but it doesn`t work.

[joeQ]

@Limer Hi, friend.

1. Dot forget to add Q_OBJECT in head of class.
2. run qmake again.

If not Ok, you could show some code in your post.

[Limer]

@joeQ

#ifndef CONFIG_BASE_H
#define CONFIG_BASE_H

#include <QPushButton>
#include <QSlider>
#include <QGridLayout>
#include <QGroupBox>

#define CONFIG_NAMESPACE_START namespace Config {
#define CONFIG_NAMESPACE_END   }

class ConfigBase : public QWidget
{
    Q_OBJECT

public:
    explicit ConfigBase(QWidget *parent = 0) : QWidget(parent)
    {
        groupBox1 = new QGroupBox(tr("Speed Control"));
        speedSlider = new QSlider(Qt::Horizontal, groupBox1);
        speedSlider->setMinimum(0);
        speedSlider->setMaximum(300);
        speedSlider->setValue(150);
        sliderLayout = new QVBoxLayout(groupBox1);
        sliderLayout->addWidget(speedSlider);

        groupBox2 = new QGroupBox(tr("Start && Pause"));
        startPushButton = new QPushButton(tr("Start"));
        pausePushButton = new QPushButton(tr("Pause"));
        resetPushButton = new QPushButton(tr("Reset"));
        startPushButton->setEnabled(true);
        pausePushButton->setEnabled(false);
        resetPushButton->setEnabled(false);
        pushButtonLayout = new QGridLayout(groupBox2);
        pushButtonLayout->addWidget(startPushButton, 0, 0, 1, 1);
        pushButtonLayout->addWidget(pausePushButton, 0, 1, 1, 1);
        pushButtonLayout->addWidget(resetPushButton, 1, 0, 1, 1);

        connect(startPushButton, SIGNAL(clicked(bool)), SLOT(start()));
        connect(pausePushButton, SIGNAL(clicked(bool)), SLOT(pause()));
        connect(resetPushButton, SIGNAL(clicked(bool)), SLOT(reset()));
    }

    ~ConfigBase()
    {}

public slots:
    void start()
    {
        startPushButton->setEnabled(false);
        pausePushButton->setEnabled(true);
        emit comboBoxEnabled(false);
    }

    void pause()
    {
        if (pausePushButton->text() == QString(QObject::tr("Pause")))
        {
            pausePushButton->setText(QObject::tr("Continue"));
            resetPushButton->setEnabled(true);
            emit comboBoxEnabled(true);
        }
        else
        {
            pausePushButton->setText(QObject::tr("Pause"));
            resetPushButton->setEnabled(false);
            emit comboBoxEnabled(false);
        }
    }

    void reset()
    {
        pausePushButton->setText(QObject::tr("Pause"));
        startPushButton->setEnabled(true);
        pausePushButton->setEnabled(false);
        resetPushButton->setEnabled(false);
        speedSlider->setValue(150);
        emit comboBoxEnabled(true);
    }

signals:
    void comboBoxEnabled(bool);

public:
    QPushButton *startPushButton;
    QPushButton *pausePushButton;
    QPushButton *resetPushButton;
    QSlider     *speedSlider;

protected:
    QGroupBox   *groupBox1;
    QGroupBox   *groupBox2;

private:
    QVBoxLayout *sliderLayout;
    QGridLayout *pushButtonLayout;
};

#endif // CONFIG_BASE_H

#ifndef CONFIG_SINGLE_LINKED_LIST
#define CONFIG_SINGLE_LINKED_LIST

#include <QCheckBox>
#include <QSpinBox>
#include <QTabWidget>
#include <QTextEdit>
#include "config_base.h"

CONFIG_NAMESPACE_START

class SingleLinkedList : public ConfigBase
{
    Q_OBJECT

public:
    explicit SingleLinkedList(ConfigBase *parent = 0) : ConfigBase(parent)
    {
        delete groupBox1;
        startPushButton->setEnabled(false);

        insertWidget      = new QWidget;
        insertPosGroupBox = new QGroupBox(tr("Position"));
        insertKeyGroupBox = new QGroupBox(tr("Key"));
        headCheckBox1     = new QCheckBox(tr("head"));
        tailCheckBox1     = new QCheckBox(tr("tail"));
        keyTextEdit1      = new QTextEdit;
        customSpinBox1    = new QSpinBox;
        keyTextEdit1->setPlaceholderText(tr("key text edit"));
        customSpinBox1->setRange(2, 10);
        QHBoxLayout *hBoxLayout1 = new QHBoxLayout(insertPosGroupBox);
        hBoxLayout1->addWidget(headCheckBox1);
        hBoxLayout1->addWidget(tailCheckBox1);
        hBoxLayout1->addWidget(customSpinBox1);
        QHBoxLayout *hBoxLayout2 = new QHBoxLayout(insertKeyGroupBox);
        hBoxLayout2->addWidget(keyTextEdit1);
        QVBoxLayout *vBoxLayout1 = new QVBoxLayout(insertWidget);
        vBoxLayout1->addWidget(insertPosGroupBox);
        vBoxLayout1->addWidget(insertKeyGroupBox);
        vBoxLayout1->setSpacing(20);

        findWidget       = new QWidget;
        findKeyGroupBox  = new QGroupBox(tr("Key"));
        keyTextEdit2     = new QTextEdit;
        keyTextEdit2->setPlaceholderText(tr("key text edit"));
        QHBoxLayout *hBoxLayout3 = new QHBoxLayout(findKeyGroupBox);
        hBoxLayout3->addWidget(keyTextEdit2);
        QVBoxLayout *vBoxLayout2 = new QVBoxLayout(findWidget);
        vBoxLayout2->addWidget(findKeyGroupBox);

        removeWidget      = new QWidget;
        removePosGroupBox = new QGroupBox(tr("By Position"));
        removekeyGroupBox = new QGroupBox(tr("or By Key"));
        headCheckBox3     = new QCheckBox(tr("head"));
        tailCheckBox3     = new QCheckBox(tr("tail"));
        customSpinBox3    = new QSpinBox;
        keyTextEdit3      = new QTextEdit;
        customSpinBox3->setRange(2, 10);
        keyTextEdit3->setPlaceholderText(tr("text edit"));
        QHBoxLayout *hBoxLayout4 = new QHBoxLayout(removePosGroupBox);
        hBoxLayout4->addWidget(headCheckBox3);
        hBoxLayout4->addWidget(tailCheckBox3);
        hBoxLayout4->addWidget(customSpinBox3);
        QHBoxLayout *hBoxLayout5 = new QHBoxLayout(removekeyGroupBox);
        hBoxLayout5->addWidget(keyTextEdit3);
        QVBoxLayout *vBoxLayout3 = new QVBoxLayout(removeWidget);
        vBoxLayout3->addWidget(removePosGroupBox);
        vBoxLayout3->addWidget(removekeyGroupBox);
        vBoxLayout3->setSpacing(20);

        tabWidget = new QTabWidget;
        tabWidget->addTab(insertWidget, tr("Insert"));
        tabWidget->addTab(findWidget, tr("Find"));
        tabWidget->addTab(removeWidget, tr("Remove"));

        mainVBoxLayout = new QVBoxLayout(this);
        mainVBoxLayout->addWidget(tabWidget);
        mainVBoxLayout->addWidget(groupBox2);
        mainVBoxLayout->setSpacing(30);

        connect(headCheckBox1, SIGNAL(stateChanged(int)), this, SLOT(slot1(int)));
        connect(tailCheckBox1, SIGNAL(stateChanged(int)), SLOT(slot2(int)));
        connect(headCheckBox3, SIGNAL(stateChanged(int)), SLOT(slot3(int)));
        connect(tailCheckBox3, SIGNAL(stateChanged(int)), SLOT(slot4(int)));
        connect(tabWidget, SIGNAL(currentChanged(int)), SLOT(tabChangedReset(int)));

    }

    ~SingleLinkedList()
    {}

public slots:
    void slot1(int state)
    {
        if (state == Qt::Checked)
        {
            tailCheckBox1->setCheckState(Qt::Unchecked);
            customSpinBox1->setValue(2);
            tailCheckBox1->setEnabled(false);
            customSpinBox1->setEnabled(false);
        }
        else
        {
            tailCheckBox1->setEnabled(true);
            customSpinBox1->setEnabled(true);
        }
    }

    void slot2(int state)
    {
        if (state == Qt::Checked)
        {
            headCheckBox1->setCheckState(Qt::Unchecked);
            customSpinBox1->setValue(2);
            headCheckBox1->setEnabled(false);
            customSpinBox1->setEnabled(false);
        }
        else
        {
            headCheckBox1->setEnabled(true);
            customSpinBox1->setEnabled(true);
        }
    }

    void slot3(int state)
    {
        if (state == Qt::Checked)
        {
            tailCheckBox3->setCheckState(Qt::Unchecked);
            customSpinBox3->setValue(2);
            tailCheckBox3->setEnabled(false);
            customSpinBox3->setEnabled(false);
        }
        else
        {
            tailCheckBox3->setEnabled(true);
            customSpinBox3->setEnabled(true);
        }
    }

    void slot4(int state)
    {
        if (state == Qt::Checked)
        {
            headCheckBox3->setCheckState(Qt::Unchecked);
            customSpinBox3->setValue(2);
            headCheckBox3->setEnabled(false);
            customSpinBox3->setEnabled(false);
        }
        else
        {
            headCheckBox3->setEnabled(true);
            customSpinBox3->setEnabled(true);
        }
    }

    void insertWidgetReset()
    {
        headCheckBox1->setCheckState(Qt::Unchecked);
        tailCheckBox1->setCheckState(Qt::Unchecked);
        customSpinBox1->setValue(2);
        headCheckBox1->setEnabled(true);
        tailCheckBox1->setEnabled(true);
        customSpinBox1->setEnabled(true);
        keyTextEdit1->clear();
    }

    void findWidgetReset()
    {
        keyTextEdit2->clear();
    }

    void removeWidgetReset()
    {
        headCheckBox3->setCheckState(Qt::Unchecked);
        tailCheckBox3->setCheckState(Qt::Unchecked);
        customSpinBox3->setValue(2);
        headCheckBox3->setEnabled(true);
        tailCheckBox3->setEnabled(true);
        customSpinBox3->setEnabled(true);
        keyTextEdit3->clear();
    }

    void tabChangedReset(int index)
    {
        startPushButton->setEnabled(false);

        switch (index)
        {
        case 0:
            insertWidgetReset();
            break;
        case 1:
            findWidgetReset();
            break;
        case 2:
            removeWidgetReset();
            break;
        }
    }

    void resetAll()
    {
        //insertWidgetReset(); //  jian cha yi xia
        findWidgetReset();
        removeWidgetReset();
        tabWidget->setCurrentIndex(0);

        reset();
        startPushButton->setEnabled(false);
    }

private:
    QVBoxLayout *mainVBoxLayout;

    QTabWidget  *tabWidget;
    QWidget     *insertWidget;
    QWidget     *findWidget;
    QWidget     *removeWidget;

    QGroupBox   *insertPosGroupBox;
    QGroupBox   *insertKeyGroupBox;
    QCheckBox   *headCheckBox1;
    QCheckBox   *tailCheckBox1;
    QSpinBox    *customSpinBox1;
    QTextEdit   *keyTextEdit1;

    QGroupBox   *findKeyGroupBox;
    QTextEdit   *keyTextEdit2;

    QGroupBox   *removePosGroupBox;
    QGroupBox   *removekeyGroupBox;
    QCheckBox   *headCheckBox3;
    QCheckBox   *tailCheckBox3;
    QSpinBox    *customSpinBox3;
    QTextEdit   *keyTextEdit3;
};

CONFIG_NAMESPACE_END

#endif // CONFIG_SINGLE_LINKED_LIST

[joeQ]

@Limer

Try include QWidget in ConfigBase head file.
and Try include QObject in SingleLinkedList head file.

run qmake again.

[mrjj]

Hi
The code is fine. Compiles here.
So if still complaining, then completely delete the build folder.

[Limer]

@joeQ

I tried, failed. this is all project : https://pan.baidu.com/s/1c2hNztm

[Limer]

@mrjj

I had deleted all build* file, but failed again and same errors. this is all project : https://pan.baidu.com/s/1c2hNztm

[Paul Colby]

Hi @Limer,

The problem appears to be that you have two SingleLinkedList classes. Although they are in two separate namespaces, for whatever reason (not sure its a bug, or a known limitation), QMake is only producing a moc file for one of them - if you rename either source file, the moc will be for the other.

I'd suggest you rename one of those classes.

Cheers.

[mrjj]

Hi
You have the file single_linked_list.h in two folders
moc seems them as one
NMAKE:-1: warning: U4004: too many rules for target 'debug\moc_single_linked_list.cpp'

so rename one of the files and it works. you can do it directly in project explorer and all
is changed correctly.

ahh @Paul-Colby beat me to it :)

[Limer]

@mrjj @Paul Colby

Thanks, it`s ok!